Many industrial processes rely on various chemical reactions in a liquid medium to achieve a certain end product. Accordingly, manufacturers and others that perform these industrial processes continually seek improvements to these processes so as to improve their efficiency and provide a cost benefit. By way of example, increasing the efficiency in chemical reactions occurring in a liquid medium may result in a decrease in processing time, which may lead to an increase in overall production and decrease in operating costs, and/or a decrease in chemical consumption in the liquid medium for achieving the desired result which may reduce operating costs. These are only exemplary and, depending of the specific application, many other benefits may be gained by improving the efficiency of various chemical reactions.
One industrial application that may benefit from improved chemical reactions is in the treatment of liquid mediums using cavitation. For example, the use of cavitation in the treatment of contaminated water, e.g., wastewater, is documented. In these cavitation methods, the goal is to generate many fine bubbles, which upon their implosion create intense, but highly localized temperatures and pressures. This energy release then causes dissolution of the water molecules and the creation of free hydroxyl radicals. The potential of these powerful radicals for the beneficial treatment of the water has been well recognized for many years. However, the inefficiencies in the known processes for generating cavitation within a liquid (e.g., ultrasonic or jet cavitation) has restricted commercial acceptance of hydraulic cavitation.
Recently, an apparatus for generating hydraulic cavitation within a liquid medium in an efficient manner has been proposed in U.S. Publication No. 2008/0099410, the disclosure of which is incorporated by reference herein in its entirety and which is assigned to the assignee of the present application. FIGS. 1-4 of the present disclosure illustrate an exemplary embodiment of a modified cyclonette 10 for generating cavitation and a liquid treatment apparatus 12 that utilizes modified cyclonette 10 to treat a liquid medium, such as wastewater, using cavitation.
In this regard, cyclonette 10 includes an insert 14 installed in the left hand end thereof and may be provided with an annular groove 16 into which an O-ring 18 may be seated. To the right of the O-ring 18, a second annular groove 20 may be formed to receive a second O-ring 22 of more or less rectangular cross-sectional configuration. Interiorly of the cyclonette 10, a flow path is provided by a throat portion 23, an inwardly tapering flow channel 24, and an outwardly tapering flow channel 26. If the exiting fluid completely fills the flow channel at its minimum diameter at point 28, the pressure within the upstream channel will be a function of the velocity head of the fluid at this point. If the absolute pressure at point 28 is at or below the vapor pressure of the fluid, or is low enough to cause dissolved gases to move out of solution, a mixed flow of gas and liquid will occur.
As a result of the outwardly tapering flow channel 26 and the momentum of the fluid, there will be a tendency for the static pressure on the wall of the channel to be reduced which in turn will result in a lower pressure within the fluid. As the fluid moves beyond point 28, the internal pressure within the gas bubbles will cause them to expand until pressure equilibrium is established.
At its left-hand end, as seen in FIG. 1, the cyclonette 10 may be provided with an internally threaded socket 30 receiving the complementary external threads 32 of the insert 14. The insert 14 has a straight sided internal bore 34 and captures and holds in place within cyclonette 10 a washer-shaped orifice plate 36 having a central orifice 37. This embodiment has shown to be productive in the formation of multiple tiny bubbles, as the liquid being treated must first constrict from the larger diameter of the insert flow passage 34 to the restricted orifice 37 and then expand again into the throat of cyclonette 10. Lastly, the cyclonette 10 may be provided with a passageway 38 extending through a wall of the cyclonette 10 into the throat portion 23. The passageway 38 may be used for the addition of a flow of the liquid being treated or a chemical or physical modifying substance in either a tangential, radial, or substantially axial direction into the throat 23.
With reference now to FIG. 2, liquid treatment apparatus 12 includes a housing 40 having cylinders 42, each having outwardly projecting annular flanges 44 to permit two or more cylinders 42 to be clamped together by bolts 46 to form a continuous, outer, annular chamber 68. At its upper end, the annular outer chamber is capped by a closure plate 50 having a lifting ring 52. The closure plate 50 is clamped to the upper end of the uppermost cylinder 42 in a manner similar to the clamping between adjacent cylinders by means of bolts 46.
With reference now to FIGS. 2 and 3, it will be seen that the lowermost cylinder 42 is attached at its lower end by means of bolts 46 to a manifold system 54. At its upper end, the manifold system 54 has an outwardly projecting annular flange 56 to which the lower most cylinder 42 is clamped by the bolts 46 as shown in FIG. 3. The manifold system 54 comprises three concentric flow channels, namely, an outer feed channel 58, a central, outwardly-flowing channel 60, and an intermediate channel 62, which may or may not be used.
As seen in FIG. 2, positioned concentrically within the outer cylinders 42 are intermediate cylinders 64 and inner cylinders 66, which are each superimposed upon each other and clamped by the clamping action between the outer cylinders, the top plate 50 and the lower annular rim 56 of the manifold system 54. It will thus be apparent with reference to FIGS. 2 and 3 that the outer and intermediate cylinders form the annular outer chamber 68 communicating with the outer feed manifold 58, an inner or central chamber 70, communicating with the manifold 60, and an intermediate chamber 72 communicating with the manifold 62.
As best seen in FIG. 4, adjoining sets of intermediate and inner cylinders may be provided with annular grooves 74 and 76 to receive any convenient sealing means. Intermediate cylinders 64 are also provided with closely spaced openings 78 to receive modified cyclonettes which may be more or less of the type shown in FIG. 1 or of various modified forms more fully disclosed in U.S. Publication No. 2008/0099410. In any case, the cyclonettes are secured in any convenient manner in the openings 78 with the opposite ends of the cyclonettes being received in openings 80 in the cylinders 66. In FIG. 4, the openings 78 are shown as having internal threads, which could receive complementary external threads on the exterior of the cyclonettes. In this regard, O-rings, such as those shown at 16 and 20 in FIG. 1, may be utilized to create seals with the cylinders 64 and 66, respectively.
However, any convenient means may be utilized to secure the cyclonettes in the intermediate and interior cylinders 64 and 66. In any case, the positioning of a cyclonette, regardless of its specific configuration, in the manner shown in FIG. 4 permits the liquid delivered through the outer manifold 58 and into the annular outer chamber 68 to flow into an insert 14 and then into the upstream end of the cyclonette and out its downstream end where it is immersed in the liquid being treated, which is being collected in the inner or central cylindrical chamber 70 and then out through the manifold 60.
As seen in FIG. 4, it is contemplated that hundreds, perhaps even a thousand or more of cyclonettes, will be arrayed in a single housing 40 of liquid treatment apparatus 12. Each cyclonette may be disposed opposite another, resulting in direct impingement of the flow from one cyclonette upon the opposite flow from an opposing cyclonette.
In use, the manifold 58 is the feed manifold for the system, delivering the liquid to be treated to the upstream or left-hand end of the insert 14 from whence the flow is ejected in an axial jet out the orifice plate 36 of the insert 14 and into the flow channel 24. This action results in the generation of shear zones that create a myriad of tiny bubbles, each of which, upon implosion, create highly localized areas of extreme pressures and temperatures.
This in turn results in dissolution of the water molecules into, inter alia, aggressive hydroxyl radicals. While in its most straightforward form the passageway 38 in the upstream end of the cyclonette will not be utilized, alternatively, a supply of the liquid being treated may be fed via the intermediate manifold 62 and the intermediate chamber 72 into the passageways 36 to provide an additional flow and hence an intensifying of the shear zone to enhance the formation of the tiny bubbles as liquid flows through the flow channel 24 of the cyclonette 10.
The cyclonette 10 and/or apparatus 12 for generating and utilizing cavitation for the treatment of a liquid medium may find application in a host of additional industrial processes. By way of example, U.S. Publication No. 2008/0277264, the disclosure of which is incorporated by reference herein in its entirety and which is assigned to the assignee of the present application, discloses using liquid treatment apparatus 12 to generate cavitation in the production of ethanol. More particularly, as disclosed therein, certain benefits may be achieved by including one or more hydraulic cavitation processing steps in a conventional dry grind process, modified dry grind process, or a wet mill process.
While the cyclonettes 10 and liquid treatment apparatus 12 as disclosed more fully in U.S. Publication No. 2008/0099410 are believed to be adequate for various applications, such as in ethanol production, there are some drawbacks. For example, while the designs disclosed in U.S. Publication No. 2008/0099410 focus on the design of the cyclonettes 10 so as to maximize cavitation generation, it may be desirable to design the liquid treatment apparatus 12 so as to optimize the collapse of the cavitation bubbles generated by cyclonettes 10. In this regard, the liquid treatment apparatus 12 as disclosed in U.S. Publication No. 2008/0099410 discharges the fluid jet containing the cavitations bubbles into a large body of fluid (e.g., chamber 70) where the cavitation bubbles will eventually collapse. While such a method provides a certain level of effectiveness in generating hydroxyl radicals in the liquid medium, more efficient methodologies of bubble collapse are being sought.